The invention relates to an approximately cuboidal or frustopyramidal, partially hollow marking or signaling element provided with a flat bottom plate, with a main body which is stiffened by ribs and which is preferably connected at two mutually opposite sides to reflecting bars.
A marking element of that kind is known from U.S. Pat. No. 4,340,419. By virtue of the bottom plate provided in that arrangement, it is relatively simple to stick it to a carriageway while the ribs on the main body afford the main body the necessary strength for it to be run over by vehicles. A disadvantage with such known arrangement however is that both the bottom plate and two non-reflecting side walls form separate parts which each have to be connected to the main body.
The applicants on the other hand have already marketed a marking element which only comprises a main body injection-molded from plastic material and two reflecting bars or strips connected thereto. Stiffening ribs form a closed grid, which means that the molding can only be removed from the mold in a downward direction so that the marking element has a plurality of downwardly open cavities and only the free ends of the ribs can be glued to a carriageway.
The object of the present invention is so to provide a marking element of the above type,that, while maintaining its static properties, can be easily manufactured. Such object is attained in that the marking element only comprises bars and a main body or base body which is integral with the bottom plate and in the interior of which a plurality of ribs extend normal to the bars, but on the other hand at most one rib extends parallel to the bars.
The main body according to the invention forms a tube whose open ends are closable by the reflecting bars. As the ribs in the interior of the tube extends in the longitudinal direction thereof, the main body can be easily removed from an injection-molding tool after production thereof in the injection-molding tool, as it is only necessary to provide a mold core which extends parallel to the tube and which finally has to be pulled out. If two such mold cores are provided, then a rib extending parallel to the reflecting bars can be arranged in the middle of the hollow body so that the ribs cross at the center of the marking element and the central region becomes particularly strong and stable.